Latobius (Mars Latobius Marmocius) is a Gaulish god known from six inscriptions found at two sites in Austria. He seems to be a god of high places of the 'Father of the Tribe' type and was the tutelary deity of the Latobici tribe.

Latobius is a deity known from six inscriptions found at two sites in Austria. These comes from St Paul (CIL III 05097 and 05098; SE 1929, 35 and 38), and Seckau (CIL III 05321) and CIL III 05320, which reads: MARTI LATOBIO MARMOGIO SINATI TOUTATI Mog[ET]IO C VAL [V]ALERINVS EX VOTO (To Mars Latobius Marmogius, Sinatis, Toutatis and Mogetius; Caius Valerius Valerianus ofers this in fulfilment of a vow). This having been found in the temple complex of the site which is on the Frauenberg. It is interestng that Latobius is invoked along with Sinatis, Teutates and Mogetius, all deities of the 'father of the tribe' type and also gods of high places. The image (above, left) ascribed to Mars Latobius was discovered in 1973 in the ruins of the former Roman city of Flavia Solva, sited close to modern-day Leibnitz in Austria. Though the statue appears to be that of a gladiator, he does posess the crested helm and spear (pilum) or fighting staff of Roman Mars as well as the shield resting against his left leg and the gladius sword (which is sometimes replaced by a fighting staff) in his left hand; all attributes of Latobius.

Latobius is a deity associated with the Vendic kingdom of Noricum in the Eastern Alps, which became voluntarily associated with the Roman Empire in 16 BCE. The origin of the Vends is still a matter of contention; however Caesar's writings indicates that they spoke a Celtic language virtually identical to Gaulish. Whether or not the people of Noricum can be considered as 'Gauls' they were speakers of a Celtic language and therefore Celts; thus Latobius was a Celtic deity (for more on Noricum and its origins see the entry on Noreia). A temple dedicated to Latobius was discovered on the site of present-day St Margarethen, Lavamuund, Austria in which was found an altar base bearing the inscription fragment: Latobivs Avgvstvs (To the Great Latobius). A further rather intriguing inscription from this selfsame sanctuary reads: Latobius Sacr[um] C[aius] Speratius Vibus et Valeria Avia pro incolumitate filior[um] suor[um] voto suscepto navale[m aedem] vetustate conlapsum restituer[unt] VSLM (Consecrated to the god Latobius, Caius Speratius Vibus and Valeria Avita, on behalf of the safety of their children, undertake the restoration of this ship temple, decayed with age. Willingly and deservedly they fulfil their vow.) This site also provided the base of a statue dedicated to Mars Latobius which has been reconstructed (above right) based on a further image recovered at Magdalensberg. At the Magdalensberg site a further clay statuette of a boatman (above left) was also uncovered. As the site itself seems to be dedicated to Latobius is has been proposed that this votive offering also represents the deity. This might provide a link to the dedication of Latobius' shrine at St Margarethen as the navale[m aedem] (Naval Sanctuary). Such a dedication seems peculiar in a land-locked realm and it may refer to an aspect of Latobius as the 'ferryman of the dead'.

Latobius was, undoubtedly the tutelary deity of the Latobici, one of the lesser two of the four main Norican tribes and though his assimilation with Roman Mars would indicate that he was a martial deity, it seems likely that he was also held as a tribal protector. This supposition gains some support from the deity's name which has been interpreted as meaning 'He who is most ardent' from the reconstructed proto-Celtic root *l?to- (furour, ardour) and the reconstructed proto Indo-European root *bhad- (best) and his second epithet of Marmocius has been interpreted as meaning 'The Large and Powerful' from reconstructed proto-Celtic roots *maro- (large) and *kom-okti- (power, wealth). Both epithets would indicate that Latobius is a deity of the 'Father of the Tribe' type; both protecting the tribe and supplying them with wealth. The possible role of Latobius as a Charon-like figure need not be incompatible with his role as a martial deity, for a warrior is well-placed to convey the spirits of the dead to the other side. Thus Latobius could have been considered as a protector both in life and in death.